The prognostic value of peripheral ischemic microvascular reserve in sepsis is not related to calcitonin gene-related peptide or substance P

OBJECTIVE: To evaluate the mechanisms attributed to the prognostic value of peripheral ischemic microvascular reserve in patients with sepsis. METHODS: This observational cohort study enrolled 46 consecutive septic patients in the intensive care unit between November 2020 and October 2021. After fluid resuscitation, the peripheral ischemic microvascular reserve was evaluated using the association of postocclusion reactive hyperemia with the peripheral perfusion index. Additionally, peripheral venous blood samples were used to evaluate the neuropeptide calcitonin gene-related peptide and substance P levels in the upper limb before and immediately after postocclusion reactive hyperemia RESULTS: There was no statistically significant correlation (p > 0.05) between basal values (pg/mL) or variations from neuropeptide levels (%) and the peripheral ischemic microvascular reserve (%). CONCLUSION: Although calcitonin gene-related peptide and substance P may have a prognostic role in sepsis, these neuropeptides do not appear to contribute to peripheral ischemic microvascular reserve.